1:17 PM PT -- Sam Rubin's station KTLA just paid tribute to their late employee -- offering up a moving tribute both online and on the air.

On X, KTLA's account posted a photo of Sam and wrote ... "KTLA 5 is profoundly saddened to report the death of Sam Rubin. Sam was a giant in the local news industry and the entertainment world, and a fixture of Los Angeles morning television for decades."

They added, "His laugh, charm and caring personality touched all who knew him. Sam was a loving husband and father: the roles he cherished the most. Our thoughts are with Sam’s family during this difficult time."

On TV, KTLA anchor Frank Buckley broke down in tears remembering his colleague -- and it made for an incredibly emotional moment. KTLA says Sam called in sick into work Friday before they learned about his sudden passing.

Sam Rubin -- the longtime entertainment reporter for the KTLA news station in Los Angeles -- has died ... TMZ has learned.

Sources with direct knowledge tell us ... Sam died Friday after being rushed to a hospital in L.A. -- specifically, UCLA West Hills. We're being told Sam suffered a heart attack at his home ... where we're told he went into full cardiac arrest.

Our sources say he was taken by paramedics sometime this morning. We're told he was transported by ambulance, but was ultimately pronounced dead.

Sam has been with KTLA since 1991 -- and he's been a mainstay in Southern California homes for decades covering entertainment, movie and TV news ... which included memorable, fun segments, celebrity interviews and insightful reports that won him multiple Emmys.

He's a highly decorated journo ... having received a Golden Mike Award, a lifetime achievement award from Southern California Broadcasters Association, not to mention once being named the best entertainment reporter by the Los Angeles Press Club.

Sam was the host of his own television show, "Hollywood Uncensored with Sam Rubin," -- which ran over 100 episodes. Sam is also one of the founding members of the Broadcast Film Critics' Association.

One of his last celeb interviews was with none other than Ryan Seacrest. Other A-listers he's chatted with on camera -- Mariah Carey, Tom Hanks, Zendaya, Bert Kreischer, Morris Chestnut, Jason Priestley, Brooke Burke, The Rock, Matt Rife, Usher, Sting and many, many more.

He's survived by his wife, Leslie, and his four children. Sam was 64.

RIP